Trending @Accenture; Notice period reduction 15 days approved

I got approval for a 15-day early release. HR told me I can either:

1. Pay for the 15 days, or

2. Adjust it against my earned leave balance (I have ~26 days/235 hrs).

My future employer has mentioned in the offer letter that they will reimburse notice period buyout if I pay for an early release. If I adjust it against earned leave, will it still be considered as a buyout by my new employer? Or could they refuse since it wasn’t a direct payment? Which option is better to ensure I can claim the reimbursement?